Effects of tannins and saponins contained in foliage of Gliricidia sepium and pods of Enterolobium cyclocarpum on fermentation, methane emissions and rumen microbial population in crossbred heifers.The International Center for Tropical Agriculture (CIAT) believes that open access contributes to its mission of reducing hunger and poverty, and improving human nutrition in the tropics through research aimed at increasing the eco-efficiency of agriculture.CIAT is committed to creating and sharing knowledge and information openly and globally. We do this through collaborative research as well as through the open sharing of our data, tools, and publications. Effects of tannins and saponins contained in foliage of Gliricidia sepium and pods of Enterolobium cyclocarpum on fermentation, methane emissions and rumen microbial population in crossbred heifers, Animal Feed Science and Technology (2019), https://doi. AbstractIncorporation of foliage and pods of tropical legumes in ruminant rations is an alternative to mitigate enteric methane emissions. The objective of this research was to evaluate the effect of adding increasing levels of ground pods of Enterolobium cyclocarpum (Jacq.) Griseb. mixed with foliage of Gliricidia sepium (Jacq.) Steud. on emissions of ruminal methane (CH4), volatile fatty acid proportions, rumen pH and microbial population in cattle. Four heifers (218 ±18 kg LW) were fed (13 days) 0, 15, 30, and 45% of pods of E. cyclocarpum mixed with foliage of G. sepium, which were supplemented to a basal ration of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. Data were analyzed as a 4×4 Latin square. After three days of CH4 measurements in open-circuit respiration chambers, rumen fluid was collected to determine volatile fatty acid (VFA) molar proportions and quantify the microbial population. Samples of ration ingredients, refusals and feces were collected to evaluate nutrient composition. Foliage and pods of legumes provided crude protein (CP), condensed tannins (CT) and saponins, while grass was characterized by higher concentrations of neutral detergent fiber (NDF). Dry matter intake (DMI) was 5.35 kg/day on average (P=0.272). Apparent fiber digestibility was reduced (81 g/kg) and digestible CP intake (13 g/kg) increased when E. cyclocarpum mixed with G. sepium in rations were given (P<0.05). Incorporation of legume foliage and pods had a linear effect on molar proportions of butyric acid and acetic to propionic acid ratio (P<0.05). Methane production, expressed on basis to digestible dry matter intake (DDMI), ranged between 43.22 and 49.94 g/kg DDMI (P=0.131) and when CH4 was related to digestible CP (347 vs. 413 g CH4 /kg DCP) or annual weight gains (0.30 vs. 0.38 kg CH4/kg weight gain, P<0.001) there were differences between the E. cyclocarpum mixed with G. sepium rations compared to the control treatment, respectively.Rumen population of total bacteria, methanogenic archaea, and total protozoa was not affected by the increasing levels of condensed tannins and saponins in rations (P>0.05).Substitut...

Potencial de los taninos condensados para reducir las emisiones de metano entérico y sus efectos en producción de rumiantes RESUMENEl metano (CH 4 ) es un gas subproducto de la fermentación de los carbohidratos en el rumen. La agricultura contribuye con el 47% de las emisiones antropogénicas de CH 4 , siendo los rumiantes responsables del 39% de las emisiones de metano entérico. Este gas de efecto invernadero (GEI) tiene un potencial de calentamiento global 25 veces más que el CO 2 y representa una pérdida de hasta el 12% de la energía total consumida por los rumiantes. Este trabajo describe los mecanismos de acción de los taninos condensados contenidos en follajes y frutos y su efecto en los microbios del rumen, así como su potencial en la mitigación de las emisiones de CH 4 . Los hallazgos sugieren que los taninos condensados reducen la población de protozoos hasta 79%, reduciendo además los metanogenos del rumen hasta en 33%. Los taninos condensados se unen a proteínas y polisacáridos formando complejos, reduciendo así la digestibilidad de la metería seca y orgánica y la producción de H 2 metabólico, el que es usado por metanogenos para la reducción del CO 2 a CH 4 . Estudios in vitro sugieren que los taninos condensados pueden reducir el CH 4 en el rumen hasta 63%, mientras que in vivo se han registrado reducciones hasta 58% en la producción de CH 4 . Además, la incorporación de taninos condensados en la ración de rumiantes tiene el potencial de aumentar la ganancia de peso en 26%, relacionando esto al aumento en el flujo de proteína de baja degradación ruminal al intestino delgado o la reducción de la energía perdida en forma de CH 4 en el rumen. Se concluye que la incorporación de taninos condensados en la ración de los rumiantes en concentración de 3-6% de materia seca puede reducir las emisiones de CH 4 así como mejorar la ganancia de peso y producción de leche de los animales productivos.Palabras clave: metano, gas de efecto invernadero, taninos condensados, leguminosas tropicales. SUMMARYMethane (CH 4 ) gas is a by-product of anaerobic fermentation of carbohydrates in the rumen of ruminant species. Agriculture contributes with 47% of anthropogenic emissions of CH 4 , being the ruminants responsible for 39% of enteric emissions of CH 4 . This greenhouse gas (GHG) has twenty-five times higher global warming potential than CO 2 and represents a loss of up to 12% of the gross energy consumed by ruminants. The aim of this review is to describe the mechanisms of action of condensed tannins contained in foliage of trees and shrubs, and their effect on rumen microbes, as well as their potential for mitigation of CH 4 emissions. The findings suggest that condensed tannins reduce protozoa population up to 79% and along with this, rumen methanogens are decreased by up to 33%. Condensed tannins bounded to proteins and polysaccharides of the ration form complexes which reduce digestibility of dry and organic matter and production of metabolic H 2 , used by methanogens to reduce CO 2 to CH 4. In vitro studies sugge...

ObjectiveThe aim of the experiment was to assess the effect of increasing amounts of Leucaena leucocephala forage on dry matter intake (DMI), organic matter intake (OMI), enteric methane production, rumen fermentation pattern and protozoa population in cattle fed Pennisetum purpureum and housed in respiration chambers.MethodsFive crossbred heifers (Bos taurus×Bos indicus) (BW: 295±6 kg) were fed chopped P. purpureum grass and increasing levels of L. leucocephala (0%, 20%, 40%, 60%, and 80% of dry matter [DM]) in a 5×5 Latin square design.ResultsThe voluntary intake and methane production were measured for 23 h per day in respiration chambers; molar proportions of volatile fatty acids (VFAs) were determined at 6 h postprandial period. Molar concentration of VFAs in rumen liquor were similar (p>0.05) between treatments. However, methane production decreased linearly (p<0.005), recording a maximum reduction of up to ~61% with 80% of DM incorporation of L. leucocephala in the ration and no changes (p>0.05) in rumen protozoa population were found.ConclusionInclusion of 80% of L. leucocephala in the diet of heifers fed low-quality tropical forages has the capacity to reduce up to 61.3% enteric methane emission without affecting DMI, OMI, and protozoa population in rumen liquor.

The objective of this work was to evaluate the effect of metabolizable energy intake (MEI) on changes in fat depots of adult Pelibuey ewes fed roughage diets under tropical conditions. Eighteen 3-year-old Pelibuey ewes with similar body weight (BW) of 37.6 ± 4.0 kg and body condition score (BCS) of 2.5 ± 0.20 were randomly assigned to three groups of six ewes each in a completely randomized design. Ewes were housed in metabolic crates and fed three levels of MEI: low (L), medium (M), and high (H) for 65 days to achieve different BW and BCS. At the end of the experiment, the ewes were slaughtered. Data recorded at slaughter were: weights of viscera and carcass. Internal fat (IF, internal adipose tissue) was dissected, weighed, and grouped as pelvic (around kidneys and pelvic region), omental, and mesenteric regions. Carcass was split at the dorsal midline in two equal halves, weighed, and chilled at 6°C during 24 h. After refrigeration, the left half of the carcass was completely dissected into subcutaneous and intermuscular fat (carcass fat). Dissected carcass fat (CF) of the left carcass was adjusted as whole carcass. At low levels of MEI, proportion of IF and CF was approximately 50%; however, as the MEI was increased, the proportion of IF was increased up to 57% and 60% for M and H, respectively. Omental and pelvic fat depots were those which increased in a larger proportion with respect to the mesenteric fat depot. Regression equations between the weight of each body fat depot and BW had a coefficient of determination (r (2)) that ranged between 0.37 for mesenteric fat and 0.87 for CF. The regression with BCS had a r (2) that ranged between 0.57 for mesenteric and 0.71 for TBF. BW was the best predictor for TBF, CF, omental fat, and pelvic fat; whereas, BCS was better than BW in predicting IF and mesenteric fat. Inclusion of both BW and BCS in multiple regressions improved the prediction for all fat depots, except for pelvic fat, which was best estimated by BCS alone. The greater slope of the regression for the pelvic fat depot equation, relative to TBF (1.40), EBW (4.02), and BCS (2.36), suggested that pelvic fat has a greater capacity to accumulate and mobilize fat. These results indicated that adult Pelibuey ewes seem to store a considerable proportion of absorbed energy in the IF depots rather than in the carcass.

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